package main

import (
	"fmt"
	"strconv"
)

func main() {
	countdown := 10

	str := "Launch in T minus " + strconv.Itoa(countdown) + " seconds"
	fmt.Println(str)

	countdown1 := 9
	str1 := fmt.Sprintf("Launch in T minus %v seconds", countdown1)
	fmt.Println(str1)

	str2 := "100a"
	countdown2, err := strconv.Atoi(str2)
	if err != nil {
		fmt.Printf("出错了\n", err.Error())
	} else {
		fmt.Println(countdown2)
	}

}
